Multiples pulse distributing system



M y 1950 I K. POSTHUMUS 2,508,538

MULTIPLES PULSE DISTRIBUTING SYSTEM Filed Nov. 22, 1946 2m. 12cm. vi1022.

KLAAS POIYZHUMUXS INVENTOR.

Ariana"! Patented May 23, 1950 UNITED asoasss MULTIPLESPULSE'DISTRIBUTING SYSTEM Klaas Posthumus, Eindhoven, Netherlands,-

signor to Hartford National Bank and Trust Company, Hartford, Comp, astrustee Application November 22, 1946, Serial No. 711,691

In the Netherlands October 13, 1945 Section 1, Public Law 690, August s,1946 Patent expires October 13,1965

4 Claims. I

In telephony and television or image telegraphy by means of pulsemodulation, both by radio means and by means of a transmission line, itis possible for a plurality of difierent signals to be transmittedsimultaneously through one channel and to be applied individually to adesired utilization device (multiplex pulse modulation). This may beeffected by arranging for the pulses of the signals to be transmittedthrough the same channel to be passed alternately and in each instancein the same sequence. In this case an arrangement is required at thereceiving end by which the signal fragments are distributed to thereceiving devices intended for them. The invention concerns anarrangement of this kind for distributing pulses to receivers arrangedfor reception of pulses whose leadingor trailing-edge or both vary inphase with respect to time and wherein the amplitude of the signalproduced is proportional to the time at which said edges of the pulseappear in the interval to it.

The arrangement, according to the invention, comprises a number ofinterconnected grid controlled gaseous discharge tubes, one such tubebeing required for each signal channel desired, the circuits of whichare each connected, to a separate receiving device in such manner thatthe latter is made operative owing to breakdown of the associatedgaseous discharge tube. The grid potential of the tubes with respect tothe cathode is so low that the tubes do not draw current and, except thefirst, do not breakdown I .even upon an increase in potential by anamount equal to the pulses to be distributed. The grid of eachsubsequent tube is connected to the circuit of the preceding tube insuch manner that upon breakdown of the latter it acquires an in--creased potential and thus also breaks down upon further increase by thepulse voltage.

. If in this arrangement the whole sequence of the pulses to bedistributed is applied to the grids of the gaseous discharge tubes, thefirst tube will breakdown upon receiving the first-arriving pulse. Thisbreakdown results in the receiving device connected to the first tubebeing made operative. The receiving device reacts on the breakdown ofthe tube in the same manner in which it would react on the first signalpulse in the case of direct control and consequently reproduces thesignal constituent to be transmitted by the said 'pulse.

Owing to the fact that upon breakdown of the first tube the second tubecoupled with it acquires an increased grid' voltage (that' is" to say aless negative grid voltage), it breaks down upon reception of the nextsucceeding pulse. At this moment it'switches on the receiving deviceconnected thereto and also raises" the grid voltage of the third tubewhich, in its turn, breaks down at the moment when the third pulsearrives, etc. Consequently with each subsequent pulse another receiveris switched on.

The mutual coupling of the grid controlled gaseous discharge tubes maybe obtained as follows: The grid of each subsequent tube is connected,by a resistor, to the cathode of the preceding tube and through a secondresistor having a high value with respect to the first-mentionedresistor and a source of negative gridvoltage, to a negative currentsupply conductor which is common to the two tubes and which isconnected, by resistors, to the cathodes of the two tubes.

The voltage variations required for operating the receiving devices maybe derived from the last-mentioned resistors.

When a complete series of pulses have been received, all the tubes areignited. Now, the first receiver must react again on the subsequentpulse. This is not possible so long as the tube connected to thisreceiver still draws current. Consequently, this current as well as thatof the other tubes must be interrupted. For this purpose, thearrangement comprises means by which the tubes, after all of them havebeen ignited, are extinguished, for example by interruption of the anodevoltage of the tubes for a short period of time. The circuit of the lasttube may in clude, for example, a quick-acting relay which The inventionwill be set out more fully by reference to the accompanying drawingshowinga schematic diagram of an example of the arrangement according tothe invention.

This executional example shows three grid: controlled gaseous'dischargetubes I, 2 and'3.'

Consequently, the device is adapted for three signals transmittedsimultaneously but, if this number is larger, it may be extended byadding a corresponding number of tubes and associated tube circuits.Threereceiving devices designated 4, 5 and 6 respectively are connectedto the cir cuits of tubes I, 2 and 3 respectively;

- The grid 1 oi-tube l is connected to the cathode F ID by a resistor 8and a source 8 of negative gridtential of tube 3. Consequently, with theinbias. Similarly, the grid of tube 2 is connected creased voltage dueto the third pulse tube 3 also to the cathode 10 of tube 2 by a resistorH and is ignited. a source l2 of negative grid-bias. The grid of At thispoint all the tubes are ignited and a the third-1; tube; is similarlyconnected to the 5 subsequentl pulse which ispintended forethe recathodeItohtub ,3 by agresistor H and a source ceiver4,;iwouldgproducej'fnogefifect if thelsituation of negative grid-biasl2. remained unchanged. Consequently, the positive The grid controlledgaseous discharge tubes, supply conductor I 3 includes a relay 2| havinghave a common positive current s1 1 1oply con: its actuating windingconnected in the anode ductor l3, by means of which the anodes are lcircuit of tube 1 3 to'open supply conductor I3 connected throughdampingresis tors,l5,v and. a-, wuppnignitionlrofytube 3. It is understood thatcommon negative current supply 'coiiductor lfi} relaylj alsoinayihaye'supplied to it the synchroby means of which the cathodes IDare connected 1 nising v signals. transmitted after completion of bycoupling resistors; Thelrec'eivers' I, Stand,- 5;. each' full'series or;signal voltages. Under the are connected by means of the la't-nientioned-:action oi thesejsfynchronising signals the relay 2! resistors. Vcauses. a short interruption of the supply of our- The grid of tube 2 isconnected to the catlrocla 91 of tube I by means of a resistor 18.Similarly; tubes ariiegative again, for they were at a posithe grid ofthe tube 3 connected by a fesister tive voltage only during the veryshort presence l8 to the cathode of tube 2. of the pulses, so thatthis'interruption prevents Thewsignalivoltages tobe distributed aregsupethetubefrom drawing. current until a'nefwe pulse plied to, thewterminalsl9 and; transferred towthe, causes'ignitioneofitubeJfagain.Insteadfofgingrid circuits.of-gthe tubes, by, means ofvtrans-vterruption'of the; current: suppliedby a supply formers20 sorthatthepulselvoltagesadd to the, deyiceto. the, tubes 2 gande3 viathe'terminalsi nthefrii'antime the grids of all of thevoltagesesuppliedsbysthejsources 9 and l2, 7 ;]2 zcand23, it. is also,possible to discontinue the.

' When now, the first. pulseg-arrives, thetubes current flowing, throughthatub'es by short-:cir 2 and .3 do not reactLto -it, since the pulsevoltage cuiting; them. a V cannotneutralise,the voltage of theusourceI2. What. I claim is:

The=grid$ Of'-. these tubes remain negative. and 1. In. a multiplexcommunication circuit arhenceithe tubesiaandfitdo not draw. The situa -rrangement for distributinga plura t op m tionisidifierent, however,fortubei. Thevoltage, lie ll transmitted ma" given sequence 'a'" oisqmceSQ-Smanasi-m berexfieeded he plurality of receiving devices" to beactuated in plflsevvflltaee-r uently. the grail of tube is, said seuence mresponse' te said pii1ses','each rendered-positivesfor;ai momentand tube I breaks pulse fl f cgbih' ve 'mj qn: down. Inthislcase ac11rrent. flowsv.through the ast geme signal} conveyed byta'j distincttra'n's' IESIStOI 11, wh ch connectsthecathode; of tube. miSSiQ-n h hfi'j ag fim 'og 5; l.:to theeconductorr: l6, and a voltage differencepending i instht' fi fi "ampntua b .s idi V arisesbetweentheiendsOfethE-Said resistor. This sigfial a first i '3' b a ou 'di'schafgefresults in the receiving device 4 receiving at the t J a g j tu H msame} moment as pulse, and thus reproducing 2.- 49-1 d a t 'gr d a qi thd ;fi' t an si nal nst tu ntheamp s s l second-of receiving devices "tobe actuated in; said" 15 dependent on the moment-atwhich thefil'Susequence each device producjng a pu c r h nt intended for ampmusedepends 'on""th timeoraetuaubn, ltrl. e., receiver.lncomprisesalfrequency or phase rmeans to couple a saild'devices 5responswe element and amphtude of the said tubes to be actuated. by the"ignition" of saidsignal generated'thereby. .is a function of the intmeans to b'ias'the'control grid is' d st,"

fi fi Which the fi l h actuate? gaseous discharge'tube 'to'acut-offvalue, means tube I occurs Inthisrespectthe rec-ewe! 4 to bias the"controlgrid of said second gaseous forms toustandardepracticefor;demodulating an discharge tube greater than impulse whosephasepositionvaries with time. 5ogm- -6 of. aid'g nd t a the grid controlled gaseousdischargetube once amplitude of said pulses, means responsive to ig-mflhntimlesvsto drawflunient- '7 V current flow in"'said'- first tube" toreduce the d Off es Voltage, of which is potential applied to the grid-(if-said second tube, in l determined Onlylby that Source and "means to"couple" said pulses' 'tothe control supply Lundergoes gin-increaseinvoltage owing 551 grids of said first and second dischargetub'es. tothe fact thatavoltage which has atendency to In a m n-, p i om unicationcircuit ar-' make said grid positive is present across resistor g m t fr st b t ng a plur nt f uses tube V 73 vproper-"110mmg of the cyclicallytransmitted iii a' given sequence" to a resistances resistors and aSuitable plurality'of receiving'de'vices tobe actuated. in value of theresistor; Iii-the grid voltage of the Said e nce i re ponse to saidpulses; each tube 4 may thus equal thelgmitial Voltage ofthe pulse insaid sequencbe'in'g derived-from an 'ihtube so that t the subsequentpulse, which telligence's'ignal conveyedy adistinct transmis addsltothis voltage-in thegrid circuit, tube 2 ig fiaf nel ndjhajvin a"time'pbsitiondepefidl also breaks down. For this purpose the resistor ing nt t nta eousa m eg a'j p;

I! must have;a..high valuelwith respect .to the. Bit-rial,thecombination:comprising in'sifecession resistance of resistor IB'. Asuitable valueior 'fi t a m m 'at an g harg wgu g;

V is a'Isuitablevalue; V

resistor H is, for-example, 10"ohms. The value charge t b "ea hbffaid geo s Qf' re istor. l3 may'then amount to' 10 0111115. The having ananode; a contro grid arid a" oath resistor I! may be smaller a'ndiorthis.1000 ohms three'fl'civi'ng' 'a' ffic j" to b' iactiiatgdijhs 'ihitWhen'whe 2 l breaks d wn. currentfl ws' e amplitude depends the timeoractuaudn;

h h the resistor. I1- which connectsthe. means to couple each ofsaidfivice's toon'ehi' h dfiz belfih s iconductor l6 and a'volte saidtubes to be actuated by? theignition ofsaid age drop occursaerossresistpr ;l' which 'rnalses tube, means to hiase theocontrol gridof said firstv V thee-racemes 5; rcspondaandraises the e-rid --p.o-1wgaseousdischarge-,tubeloa cuteofi value, means '70;sequence)"each'devicef'pro'd'ucinga 'volta'gewhdse to bias the controlgrid 01' said intermediate gaseous discharge tube to a value greaterthan the sum of the cut-oil bias of said intermediate tube and theamplitude of said pulses, means to bias the control grid of said finalgaseous discharge tube to a value greater than the sum of the cutoilbias of said final tube and the amplitude of said pulses, meansresponsive to current flow in said first tube to reduce the potentialapplied to the grid of said intermediate tube, means responsive tocurrent flow in said intermediate tube to reduce the potential appliedto the grid of said final tube, and means to couple said pulses inparallel to the control grids of said succession of gaseous dischargetubes.

3. A circuit arrangement for distributing a plurality of pulsescyclically transmitted in a given sequence to a plurality of receiversto be operated in sequence in response to said pulses,

comprising in succession a first, an intermediate and a final gaseousdischarge tube, each of said gaseous discharge tubes having an anode, acontrol grid and a cathode, means to apply a direct current potentialbetween the anode and the cathode of each of said tubes, a resistorinterposed between the positive pole of said potential means and theanode of each of said tubes, a second resistor interposed between thenegative pole of said potential means and the cathode of each of saidtubes, a plurality of receivers to be operated in said sequence, each ofsaid receivers being coupled across the cathode resistor of one of saidtubes and being actuated by the ignition of said tube, means to bias thecontrol grid of said first gaseous discharge tube to a cut-oil value,means to bias the control grid of said intermediate discharge tube to avalue greater than the sum of the cut-off bias of said intermediatedischarge tube and the amplitude of said pulses, means to bias thecontrol grid of said final discharge tube to a value greater than thesum of the cut-ofl bias of said final tube and the amplitude of saidpulses, a plurality of transformers, the secondary windings of saidtransformers being interposed in' the grid circuit of said dischargetubes and the primary windings being connected in parallel to couplesaid pulses to the control grids of said discharge tubes, a gridresistor interposed between the grid biasing means and the transformersecondary winding of the grid circuit of each of said tubes, a thirdresistor coupling the cathode of said first discharge tube to thejunction of the grid resistor and the transformer secondary winding ofsaid intermediate discharge tube, a fourth resistor coupling the cathodeof said intermediate discharge tube to the junction of the grid resistorand the transformer secondary winding of said final discharge tube, anda relay, the actuating winding of said relay being interposed in theanode circuit of said final tube and the contact elements of said relaybeing interposed in the direct current application means to interruptthe supply of direct current potential in response to current fiow insaid final discharge tube.

4. An arrangement, as set forth in claim 2, further including meansresponsive to current flow in said final tube to extinguishsimultaneously all of said gaseous tubes.

KLAAS POSTHUMUS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,282,046 Goldsmith May 5, 19422,310,105 Michel Feb. 2, 1943 2,373,134 Massonneau Apr. 10, 19452,402,372 Compton June 18, 1946 2,412,642 Wilkerson Dec. 17, 1946

